<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <script src="vue.js"></script>
    <style>
        .one{
            width: 200px;
            height: 400px;
            background-color: aqua;
        }
        .two{
            width: 200px;
            height: 500px;
            background-color: rgb(11, 14, 13);
        }
    </style>
</head>
<body>
    <div id="app">
        <p :class="classP"></p>
    </div>
    <script>
        let vm = new Vue({
            el:"#app",
            data:{
                classP:"one"
            }
        })
    </script>
</body>
</html>